CVE-2022-20587 in Android
Summary
by MITRE • 12/16/2022
In ppmp_validate_wsm of drm_fw.c, there is a possible EoP due to improper input validation. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-238720411References: N/A
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Analysis
by VulDB Data Team • 04/22/2026
The vulnerability identified as CVE-2022-20587 resides within the drm_fw.c file of the Android kernel, specifically in the ppmp_validate_wsm function. This represents a critical security flaw that enables local privilege escalation without requiring any additional execution privileges or user interaction for exploitation. The issue stems from inadequate input validation mechanisms that fail to properly verify the legitimacy of data structures being processed within the kernel space.
The technical flaw manifests as an improper validation check within the ppmp_validate_wsm function where the system fails to adequately validate input parameters before processing them. This validation gap creates an opportunity for malicious code to manipulate the function's behavior and potentially execute arbitrary code with elevated privileges. The vulnerability operates at the kernel level where privilege escalation can occur without the need for user interaction, making it particularly dangerous as it can be exploited by any local user with basic access to the system. This type of vulnerability falls under the CWE-20 category of "Improper Input Validation" and represents a direct pathway for attackers to elevate their privileges from standard user level to kernel level access.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with complete control over the affected system. Once exploited, the local attacker gains the ability to execute arbitrary code with the highest system privileges, potentially allowing for complete system compromise, data exfiltration, or further lateral movement within the network. The absence of user interaction requirements makes this vulnerability particularly concerning as it can be exploited automatically without any human intervention. From an attack perspective, this aligns with the ATT&CK technique T1068 which covers "Exploitation for Privilege Escalation" and represents a classic local privilege escalation vector that could be leveraged in various attack scenarios.
Mitigation strategies for CVE-2022-20587 should prioritize immediate patching of affected Android kernel versions through the standard security update mechanisms provided by device manufacturers and Google. System administrators should implement comprehensive monitoring to detect any anomalous privilege escalation activities that might indicate exploitation attempts. The vulnerability's nature suggests that any system running an affected kernel version is immediately at risk, making prompt patch deployment essential. Organizations should also consider implementing additional security controls such as kernel module signing enforcement and runtime integrity checks to prevent exploitation attempts. The vulnerability's classification as a local privilege escalation means that traditional network-based security measures may not prevent exploitation, requiring more robust endpoint protection and system hardening practices to provide defense in depth.